Centrifugation is a process commonly used to separate particles in a sample for isolation or analysis of the particles. In a conventional centrifugation operation, sample tubes or bottles are placed in a rotor, and the centrifuge spins the rotor at a desired rotational speed (rotor speed) in an enclosed chamber. As a safety feature, some centrifuges include a door to the chamber and a latch that secures the door in a closed position during the centrifugation operation. Some centrifuges also include a safety switch that prevents the centrifuge from spinning the rotor when the door is unlocked. These features help prevent exposure of lab personnel to the physical hazards of a spinning rotor.
Some centrifugation operations, however, require a user to access and work on a spinning rotor. For example, a zonal centrifugation operation includes performing manual tasks on a spinning rotor. During the loading step of the operation, a sample is loaded onto a density gradient. This step involves the user to deliver the sample into the rotor and install/remove the fill apparatus while the rotor is spinning. The rotor speed is then increased to a running speed, where the desired particle separation through the density gradient is achieved under vacuum. Finally, the rotor speed is reduced to an unloading speed, the fill apparatus is manually re-installed onto the rotor, and the separated sample is unloaded while the rotor spins. To accomplish the loading and unloading steps, safety features, such as the safety switch or door latch described above, must be deactivated. Consequently, the user is exposed to the risk of injury from the spinning rotor or leaking sample during operations like zonal centrifugation operation.
Workflow in a laboratory can be disrupted if a centrifuge malfunctions; but an instrument cannot be under constant observation. For example, there may be a number of centrifuges located throughout a laboratory, a building, or a campus. Also, some centrifugation operations, like isolation of high-purity plasmid DNA, may take hours to complete. So, a user may or may need to leave a centrifuge unattended for some time. Therefore, laboratory users, technicians, scientists and supervisors desire functionalities that monitor and/or provide diagnostic information about these instruments to ensure that operation is proceeding safely, and if necessary, to take action.
Accordingly, it is an object of the present invention to provide improved methods, apparatus, and systems to address the problems described above.